DALTON, JOHN (1766-1844). A celebrated English chemist and natural philosopher, born at Eaglesfield, near Coekermouth. in Cumber land. Ile received his early education in the school of his native place, and, after 1781, in a boarding-school kept by a relative in Kendal. Here his love of mathematical and physical studies was first developed. He wrote several mathematical essays, and in 1788 eommenced journal of meteorological observations, which he continued throughout his whole life. In 1793 he was appointed teacher of mathematics and the physical sciences in the new college at Man chester, where he chiefly resided during the re mainder of his life, though frequently employed, „after 1804, in giving lectures on chemistry in several large towns. in the years 1808 to 1810 he published his :Veit' System of Chemical Philos ophy (2 parts. London). to which he added a third part in 1827. In 1817 he was appointed president of the Literary and Philosophical So ciety at Manchester. He was also a member of the Royal Society. and of the Paris Academy, and in 1833 received a pension of £150, after wards raised to £300. In the same year Dalton's friends and fellow-townsmen collected £2000, to mice a statue to his honor, which was executed by Chantrey, and placed at the entrance of the Royal Institution in Manchester. Dalton was also honored by the University of Oxford with the degree of D.C.L., and with that of LL.D. by
the University of Edinburgh. His chief physical researches were those on the constitution of mixed gases, on the force of steam, on the elasticity of vapors, and on the expansion of gases by heat. In chemistry he distinguished himself by his progressive development of the atomic theory (sec CEEMISTRY), as also by his researches on the absorption of gases by water, on carbonic acid, •arburetted hydrogen. etc. His papers are mostly contained in the Memoirs of the Lit erary and Philosophiea4 Society of Manchester, the Philosophical Transactions, Nicholson's Philosophical Journal, and Thomson's Annals of Philosophy. Besides these, we have his Meteoro logical Essays and Ohserrations (London, 1793; 2d ed. 1834). Profound, patient, and intuitive, Dalton had precisely the faculties requisite for a great scientific discoverer. His atomic theory has revolutionized the science of chemistry and has yielded a greater number of valuable results than, perhaps, any other idea ever introduced into physical science. In his habits, Dalton was simple: in his manners, grave and reserved, but kindly, and distinguished by his truthfulness and integrity of character. Consult Roscoe and Harden, A New lieu: of the Origin of Dalton's Atomic Theory (New York, 1896).